Studies are proposed on axonal transport and transneuronal transfer to further understanding of the development and maintenance of synaptic connections. Axonal transport, the process by which macromolecules synthesized in the nerve cell body are conveyed to other regions of the cell, is especially important during axonal elongation and synaptic development when protein demand is high and composition changing. Furthermore, speculation abounds that the fraction of transported material that is transferred transneuronally may subserve a trophic or informational role in the receiving cell. A retrogradely transported component is thought to carry information about the changing environment of the nerve ending. Experimental approaches in this proposal are centered on analysis of axonally transported proteins and on quantitation of transport rates and transneuronal transfer, both before and after the onset of functional visual activity. Particular attention will be given to synaptosomal membrane proteins, including the (Na ion plus K ion)-dependent ATPase, and to fibrillar neuronal proteins. The plasticity of both retrograde transport and transneuronal transfer in response to neonatal visual system trauma will be evaluated. The proposed study has significance for understanding development and repair mechanisms in the nervous system and forms a basis for future work on rehabilitation of severe visual impairments, such as glaucoma.